Water quality modelling: microbial risks associated with manure on pasture and arable land

Abstract

While agricultural activities, such as the application of manure on arable land and animal grazing on pastures, provide economic and environmental benefits, they may also pose microbial risks to water sources. The aim of this paper was to study the microbial fate and transport in an agricultural catchment and recipient water source through further development of the hydrological model HYPE. Hydrological modelling was combined with hydrodynamic modelling to simulate the fate and transport of Salmonella spp., verotoxin-producing Escherichia coli O157:H7 (VTEC) and Cryptosporidium parvum in an agricultural catchment of a drinking water source, Lake Vombsjön, in Sweden. This approach was useful to study the influence of different processes on the pathogen fate and transport, and to interpret the relative changes in the simulated concentrations. Sensitivity analysis indicated that the largest uncertainties in the model were associated with the estimation of pathogen loads, parameterisation of the pathogen processes, and simulation of partitioning between surface runoff and infiltration. The proposed modelling approach is valuable for assessing the relative effect of different risk-reducing interventions.

An agent-based model that simulates the spatio-temporal dynamics of sources and transfer mechanisms contributing faecal indicator organisms to streams. Part 1: Background and model description

“…Hodgson et al, 2009), a current lack of information (c.f. Sokolova et al, 2018) dictates this parameter be specified for the type of FIO being modelled. If the FIO-agent is detached, then Detachedfaeces is set to "1" so that the Surface Routing Sub-model can run (Figures 4b and 6).…”

Molecular Analyses of Fecal Bacteria and Hydrodynamic Modeling for Microbial Risk Assessment of a Drinking Water Source

“…The model consists of continuity, momentum, temperature, salinity, and density equations, and is closed using a turbulent closure scheme. The application of this model to Lake Vomb has been described by Sokolova, Lindström, Pers, Strömqvist, Lewerin, Wahlström, and Sörén [22]. In brief, the model was set up and validated to simulate the conditions during the year 2015.…”

“…ECO Lab used flow fields from the hydrodynamic model to calculate the pathogen concentrations in the lake. Due to the lack of knowledge on ssrA decay in water, the contaminant decay was described in the model assuming a half-life time of 3 days-this value is representative for decay of culturable bacteria, as summarized in [22].…”

“…However, the suppliers have difficulties estimating putative pathogen concentrations at the water intake, due to sparse monitoring of pathogens and lack of quantitative data. Thus, to support risk assessment and evaluate risk reduction measures, fate and transport modeling of FIB and pathogens has been applied [18][19][20][21][22]. In Sweden, coupling fate and transport modeling with QMRA is still relatively rare, but some examples exist [23] and simplified methods have been developed for practical application to meet the increasing interest and need, see e.g., Åström and Johansson [24], Åström, Lindhe, Bergvall, Rosén, and Lång [17].…”

Monitoring of drinking water from the karst springs of the Ljuberadja-Niš water supply system (Serbia)

“…The latest study performed in Indonesia estimates that the greatest risks of intestinal infections appear as a result of fecal contamination in spring and well water [14]. Agricultural activities such as the application of manure to arable land and grazing cattle in pastures offer economic and ecological advantages, but on the other hand, they pose a risk of microbiological contamination in water springs [32]. Escherichia coli (E. coli), which is an indicator of fecal contamination, is part of the microbiological flora of human and animal feces, and it can be found in wastewaters, all natural waters and in the ground.…”